The invention relates to a differential housing for the axle drive of a motor vehicle comprising a drive-gear, at least two rotationally symmetric stamped housing parts, impressed bearing projections for mounting a differential pin, and axle drive shafts extending transversely with respect to the differential pin and having a rotational axis.
A demountable differential housing composed of two identical stamped housing halves is known from German Patent 462127, the connecting flanges of said housing having impressed projections. Two circular projections located radially opposite one another in the assembled state form a bearing lying in the separating plane for a differential pin while a drive gear abuts one half of the housing at a plurality of projections that are closed relative to the circumferential edge of the flange. This gear is held by screw connections which additionally connect the housing halves.
A goal of the invention is to provide a differential housing made of stamped parts which can be manufactured efficiently with simpler design, whereby a high rigidity of the housing is also achieved.
This goal is achieved by providing an arrangement wherein a first one of the housing parts is made in the form of a bearing part provided with a jacket extending essentially at a continuous incline relative to the rotational axis and having a section with the impressed bearing projections for a differential pin wherein a first one of the housing parts is made in the form of a bearing part provided with a jacket extending essentially at a continuous incline relative to the rotational axis and having a section with the impressed bearing projections for a differential pin, wherein the drive gear is mounted on a flange surrounding an opening in the first housing part, said opening being closed by at least one additional housing part formed as a cover.
When a part of the differential housing is designed as bearing part which has a jacket extending essentially continuously inclined relative to the rotational axis of the axle drive shafts, in which jacket the projections for mounting the differential pin are disposed, the conically tapered jacket permits the use of deep-drawn steels, especially readily deformable fine-grain steels. These can be shaped simply and economically on a mass production basis. The opening provided through the conical jacket also allows simple installation of the components to be mounted in the housing. The arrangement of the drive gear on a flange of the bearing part that surrounds the opening ensures a direct power flow into this housing part which has a high degree of rigidity thanks to the closed jacket. This jacket is interrupted only by the projections in which the differential pin is mounted. These projections have no separating plane, so that the torque initiated through the drive gear is transmitted to the differential pin without any possible deformations or displacements of the housing parts bordering such a separating plane.
The opening is closed by at least one cover so that a closed rigid housing results supported in the area of the drive gear.
Advantageously, the bearing part can additionally have a supporting surface which receives the forces of a differential gear acting in the direction of the rotational axis. Thus, in addition to the differential pin holding the compensating gears, one of the differential gears is supported in the bearing part. The supporting surface can be produced when stamping the bearing part, so that no additional manufacturing step is required.
The arrangement of the flange for mounting the drive gear in a radially outward area, because of the relatively large diameter, reduces the forces conducted into the flange by the applied torque.
Advantageously, the cover can have another support surface for a second differential gear, either directly or with interposition of an insert.
In order to mount the differential housing rotatably in simple fashion and economically in an axle housing, both the bearing part and the cover can have sections that run parallel to the rotational axis and are designed as bearing seats.
With increased requirements as to rigidity, especially in the area of the differential pin bearing, a bearing seat can be provided on a separate bushing fastened to the bearing part.
The cover can be made essentially roof-shaped in cross section, whereby the peak of the roof is mounted on an inner surface of the flange bearing the drive gear, and is disposed on one of the bevels of the additional supporting surface.
In order to decrease further the requirements for precision in manufacturing the differential housing, the compensating gears or the differential gear can be mounted at a distance from the inner surface of the jacket or supporting surface, so that the resultant space is filled during assembly by injecting liquid plastic, for example thermoplastic plastic or thermosetting plastic. After the plastic sets, the compensating or differential gears abut the inner surfaces or supporting surfaces with interposition of this plastic. Hence, an exactly fitting and plane running surface for these gears is not required.
Further advantageous simplifications are realized by eliminating one possibility for disassembly by permanently connecting the parts forming the housing with one another or with the drive gear. This dispenses with the otherwise conventional cutting of bolts and threads in the drive gear and in the housing, tightening of bolts, their corresponding tightening torque and rotational angle check, the bolt connection, and the bolts themselves. By avoiding undesirable thermal inertia, connection is preferably accomplished using laser welding so that the conduction of heat into the parts to be connected remains low.
The bushing bearing the bearing seat can be connected economically and simply by friction welding with the bearing part.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.